EFI Heat Management

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EFI Heat Management

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EFI Heat Management - 3/19/2006 8:02:12 PM

HDF Tech

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Joined: 5/14/2005
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Injected Twin Cam High Temperature Idle

The 2002 and later fuel injected Twin Cam engines use a three phase heat management system to reduce engine temperature under extreme conditions. Be aware that a rider with a very hot engine may notice the affects of this three phase heat management system and incorrectly assume an idle problem exists.

Phase 1 - At approximately 320˚ F the ECM will gradually reduce engine idle speed until the engine temperature drops or the engine reaches 800 rpm.

Phase 2 - If engine temperature reaches 338˚ F the ECM richens the air/fuel ratio to provide additional cooling.

Phase 3 - If the engine temperature reaches 356˚ F fuel injector pulses are interrupted. The air drawn in and expelled helps cool the engine further. Since there is no combustion it would be perceived as a misfire. This third stage will only happen when the motorcycle is stationary.

These are head temps as indicated and NOT oil temps

Reference: H-D Owner's Manual.